The invention relates to an apparatus and method for changing printing plates with a printing plate cartridge for a printing press.
Rotary printing presses have multiple printing groups, with each printing group having several, in particular four, printing units. Each printing group includes a transfer cylinder, a plate cylinder, an inking system, and, optionally, a dampening system. Preferably, printing plates embodied as printing blocks are positioned on the plate cylinders and transfer forms, preferably embodied as rubber offset blankets, are positioned on the transfer cylinders. The form cylinders are also described as plate cylinders and the transfer cylinders as rubber cylinders. If, for example, a change in production must be made to the printing press, among other things, it is necessary to remove an old or used printing plate from a plate cylinder and replace it with a new or unused printing plate. In so doing, the old printing plate that has been replaced is transferred to a printing plate cartridge, with the new printing plate to be installed being held in readiness in the printing plate cartridge.
German Patent Document No. DE 10 2004 022 089 A1 and European Patent Document No. EP 1 391 300 A1 both disclose printing plate cartridges for a printing press having an old case for accommodating printing plates to be removed when changing printing plates and a new case for accommodating printing plates to be installed when changing printing plates. These printing plate cartridges, which are known from the prior art, are mounted on a machine frame of the printing press in a pivotable or rotatable fashion, with each printing plate cartridge serving only one printing unit of a printing group when changing printing plates.
Therefore, according to this prior art, one individual printing plate cartridge must be provided for each printing unit of a printing group. This may lead to problems with the available space in a printing press. Moreover, the printing units have relatively poor accessibility.
Based on this prior art, the object of the present invention is to produce a new type of printing plate cartridge for a printing press.
According to the invention, the printing plate cartridge is mounted in such a way that it may be pivoted in a rotating fashion and moved in a linear fashion, both relative to a printing group of the printing press, such that the printing plate cartridge is able to service multiple printing units of the printing group when changing printing plates.
Using the printing plate cartridge according to the invention, it is possible for multiple printing units of one printing group to be serviced when changing printing plates; thus, when changing printing plates, it is possible to accommodate printing plates that are to be removed from multiple printing units on one side and to hold printing plates in readiness that are to be installed in multiple printing units. This will reduce the space required for the printing plate cartridges. Moreover, the printing units of the printing groups will become lighter as well as more easily accessible.
Preferably, the printing plate cartridge has an outer part that is mounted on a machine frame or a web guide wall and an inner part that is housed inside the outer part, with the outer part and inner part being pivotable together in a rotational fashion relative to the printing group of the printing press and movable in a linear fashion, with the inner part being movable in a linear fashion relative to the outer part, and with the inner part having the cases for accommodating the printing plates.
According to an advantageous embodiment of the invention, the printing plate cartridge has a gripper device for gripping printing plates when changing printing plates, with the gripper device being attached to at least one conveyor chain and being movable along the conveyor chain or each of the conveyor chains, and with the conveyor chain or each of the conveyor chains being guided in a chain guide bar system. The chain guide bar system has first sections, assigned to the outer part, and second sections, assigned to the cases in the inner part, with the first and second sections expanding dependent upon the position of the inner part relative to the outer part in such a way that the gripper device attached to the conveyor chain or each of the conveyor chains may be retracted into the cases of the inner part dependent upon the position of the inner part relative to the outer part.
Preferred embodiments of the invention may be found in the description provided below. One exemplary embodiment of the invention will be described in greater detail with reference to the drawings, without limiting the scope of the invention.